β-SiC nanowires with large scale have been synthesized successfully via a chemical vapour deposition (CVD) method at 1300 °C without using catalysts, templates or extra gases. X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), Fourier transform infrared spectroscopy (FT-IR) and energy-dispersive X-ray spectroscopy (EDS) were used to characterize the phase and the morphology of the as-prepared products. Characterization of the as-synthesized nanowires indicated that they were made up of a crystalline SiC core coated with an amorphous SiO₂ shell. A vapor–solid (VS) growth mechanism was proposed for the growth mode of the as-grown SiC/SiO₂ nanowires. The photoluminescence (PL) spectrum of as-obtained nanowires exhibited a significant blue shift compared with the bulk SiC. When the reaction temperature was changed (1200 °C, 1400 °C, 1500 °C), low production or irregular morphology of the nanowires was obtained. The diameter of nanowires synthesized with catalyst was narrower between 20–40 nm while that without catalyst was about 50 nm. The as-synthesized products have potential in future blue-green emitting device applications. This research will also be helpful in simplifying the synthesis of SiC-related nanostructures.